Youth homeless is soaring. That's perhaps not entirely unexpected, given the economic climate, but it's worth looking more closely at those figures, and considering why they are soaring, why they are likely to continue to rise, and what the consequences will be for vulnerable young people. It's not a pretty sight.

• Nearly half of homelessness services (44%) and councils (48%) have seen an increase in young people seeking help because they are homeless or are at risk of becoming homeless
• The number one cause for homelessness among this age group is relationship breakdowns with family and friends, and cases of this have increased
• The majority (62%) of young homeless clients seen by charities were not in education, employment or training, [and] 46% were in financial difficulties
• A quarter of young clients (26%) seen by services had experience of sleeping rough.

A rise in youth homelessness is just one side of the equation, however. The other is how charities and local authorities are coping with the demand. This is what the survey found:

• 48% of homeless agencies reported turning away young single homeless people because their resources were fully stretched;
• Nearly one in five local authorities (17%) feel they are not meeting their legal requirements for homeless young people aged 16-17;
• Half of local authorities report using B&Bs [bed and breakfasts] as emergency accommodation for young people, despite Government guidelines which advise against their use;
• More than 70% of local authorities said they had no shared accommodation private sector provision for young people, despite this being the only option for young people on housing benefit; and
• 53% of homeless agencies have experienced closures or threats of closure to youth services in their area.

Dig deeper into the data on youth homelessness contained in the report and it gets no less alarming. The latest CHAIN figures compiled by the Broadway charity, which record rough sleeping in London, show that after three years of relative stability, the number of under-25 years olds on the street has spiked alarmingly:

"In the space of eight months from 1 April to 27 November 2011 CHAIN recorded 421 rough sleepers under 25. This is already a 32% increase on the number of young people rough sleeping in London within the 12 months of 2010/11... Within the under 25s, the biggest increase is found in the 18–21 age group. There were 211 rough sleepers aged 18 to 21 recorded between April and November 2011, and 139 recorded between April 2010 and March 2011. This means that the number of 18 to 21 year olds seen rough sleeping in London in the last eight months is already 52% higher than that seen in the whole of the previous year."

The Homeless Link survey (extrapolating from returns provided by 79 frontline homeless providers and 108 local authorities) estimates that in October and November 2011, approximately 16,000 young people were being supported by homeless charities. In October, 13,000 young people presented as homeless to local authorities or sought housing advice or information in October 2011 (a rate of approximately 400 a day across England). How that compares with previous years isn't shown. But almost half of both providers and councils say under-25's were increasing as a proportion of the homeless people they had contact with.

Some of the reasons why young people presented as homelessness over the past 12 months are pretty much unchanged from the previous year: domestic violence or abuse; poor housing conditions; and eviction. The big change relates to issues whose impact and prevalence have been - we might reasonably suspect - amplified by the economic downturn and growing household financial pressures: relationship breakdown with family and friends; drug and alcohol problems; and mental illness.

As demand rises, however, the capacity of local authorities and the voluntary sector to respond has shrunk dramatically: there was a 25% average cut in funding for homeless charities in 2011-12 (a quarter of whom say they can now support less homeless people as a result); funding for supported housing (which between provides essential homelessness prevention work) has been slashed. As the report says:

"All these changes in combination are creating the perfect storm for an increase in homelessness amongst young people, especially the most vulnerable, and with severe consequences. Young people experiencing homelessness can develop mental and physical health problems, accumulate problem debt, become more vulnerable to crime and find access to employment and learning further diminished."

Young people driven out of a their current home by benefit cuts will be expected to find a cheaper option, most likely a room in a shared house. But the Homeless Link survey reports that this kind of accommodation is in desperately short supply in many areas, and even where it exists there is a resistance on behalf of private sector landlords to deal with young people claiming benefits. Unless this bottleneck is eased, it says, many young people "would have no option but to sleep rough".

Rising youth homeless, it says, "does not need to be an inevitable conclusion of the current financial climate". But how do you stop it? The report calls on the DWP to build safeguards into its welfare and benefit reforms to avoid "pushing already difficult family situations over the edge". It urges investment in early intervention projects - not least in family mediation services - to try to stem the expected flow of young people heading for the streets.

This looks unlikely. But the report has a sharp back-to-the-future warning about the consequences of ignoring these calls to action, which will have a vivid resonance for anyone who remembers what happened the last time a Conservative prime minister oversaw public spending cuts on a scale comparable to the present ones:

"This [early intervention and preventative action] is essential if we want to avoid a return to the levels of youth homelessness seen in the late 1980s."